With several large housing developments looming in southern Howard County, a local land-use panel recommended yesterday law changes that some slow-growth advocates fear will create suburban sprawl.

The technical changes, proposed by the county's Planning Board yesterday, relate to land designated for "mixed-use" or Columbia-style development. Under mixed use, developers must build a combination of housing, open space and businesses.

The proposed changes -- which must be approved by the county's Zoning Board -- could allow developers to build almost half of the houses planned for their projects without building any of the businesses.

"I'm afraid too much residential will get built," said Bill Waff, president of the Howard County Community Association and the Savage Community Association. "I'll be paying attention, especially if the Rouse Co. has the MXD [mixed-use site]."

Rouse has one of the potential sites -- 526 acres off Gorman Road in North Laurel -- where it plans to develop a Columbia-style community that would be about half the size of one of the planned community's villages in terms of the number of dwellings.

The company plans to develop 37 percent of the site for single-family houses; 12 percent for townhouses, apartments and condominiums; 36 percent for open space; and 15 percent for businesses. Construction would begin in 1999.

Two Rouse officials, Joe Necker and Jim Lano, attended yesterday's Planning Board meeting. Lano, an attorney, referred questions from a reporter to Rouse spokeswoman Kathy Lickteig, who could not be reached for comment after the meeting.

Land-use officials, however, said yesterday that the proposed changes are proper.

For example, if the housing market is outpacing the business development market, developers should be allowed to at least start their mixed-use projects, said Ted Mariani, chairman of the Planning Board.

"You don't want to have a project that is just sitting there that someone can't even get off the dime with," Mariani said. "There are still plenty of controls."

Under current regulations, developers can be required to track all types of development at the same time, Mariani said. Columbia could not have been built under such strict controls, he said.

Under the proposed changes, a developer could construct up to percent of the site's residential lots before developing a "reasonable" level of commercial lots. After developing 70 percent of the residential lots, the developer must show a "significant" level of commercial development.

There are other controls. For for each project, county land officials control a "staging plan," which gives them the power to stop a project that lacks the appropriate mix of uses, Mariani said.

Still, Democratic state Del. Shane Pendergrass of Columbia is concerned that the county is giving up too much. She said that business development is crucial for Howard's tax base.

Flexibility is fine, she said, but "there has to be some point at which flexibility ends and the fiscal health of the county becomes the primary concern."

Two other potential mixed-used developments are planned for southern Howard: Cherrytree Park and a Fulton-area site.

Cherrytree Park, a 42.5-acre site at U.S. 29 and Route 216, is further along in the county approval process than the Rouse project and could be open to residents in 1999.

If approved, it would include as many as 33 single-family detached homes, 114 townhouses, 120 multifamily units, about 10,000 square feet of retail space and about 14,000 square feet of office space.

The Fulton-area site is a 700-acre tract off U.S. 29 from Johns Hopkins Road to Route 216. Overall plans for this project have not been filed with the county.

In other business at yesterday's Planning Board meeting:

The board approved a "label change" for Rouse's plans to develop River Hill, its ninth and final village in Columbia.

Originally, according to Rouse and county land-use officials, Rouse labeled a River Hill tract as "single-family medium density" and designed its lots accordingly. Subsequent Rouse documents described the tract as single-family low density, an unintentional mistake, according to Rouse. The board changed its documents to reflect the original "single-family medium density."

But members of the River Hill village board remained concerned that new Rouse plans will increase the number of lots in the tract from 883 to 914, which could reduce property values. "The Village Board views the [label change] with more skepticism and concern than others might," said Jennifer Blake, a board member.

The board approved a plan to build a gas station, convenience store and carryout restaurant along U.S. 40, several blocks east of Rogers Avenue.

Although the site recently has been vacant, there was a gas station there for more than 20 years, county planning officials said.

Nearby residents objected to the plan, telling the board that gas stations are too noisy.

Joseph Day, president of the Chestnut Hills Association, said that "in recent years, there have been incidents when patrons and others on the site have urinated into the drainage stream located on the border of our two properties."

Board members said the site is properly zoned and that they were pleased with plans to build a fence around the site.